Dietary bioavailability of uranium to a model freshwater invertebrate

Environmental Science and Technology
By: , and 

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Abstract

Uranium (U) mining increases environmental exposures. Understanding how U is taken up by organisms can aid in evaluating the potential for bioaccumulation and toxicity. Although the importance of aqueous geochemical speciation is well recognized for U bioavailability after dissolved exposures, far less is known about the processes controlling U bioavailability after dietary exposures. This study characterizes the biogeochemical drivers of dietary U uptake in the freshwater snail Lymnaea stagnalis in laboratory experiments. Solids tested included benthic diatoms pre-exposed to dissolved U(VI), soils from contaminated U mine sites, and colloidal hydrous ferric oxide (HFO) synthesized in the presence of dissolved U(VI) or with U complexed by natural organic matter (NOM). Results showed that U was bioavailable from all solids. Uranium assimilation efficiency (AE), a proxy for dietary U bioavailability, varied among solids. AE was lowest for the U-contaminated soils (25 ± 17%) and highest for the U-laden diatoms (71 ± 13%). AE varied slightly among HFO preparations, suggesting modest influences of NOM and iron on U bioavailability. Increases in dietary U exposures reduced feeding rates, and the extent of feeding inhibition appeared inversely related to U bioavailability. The high U assimilation and range of bioavailability have implications for toxicity risks inferred without considering dietary uptake.

Suggested Citation

Croteau, M.N., Fuller, C.C., Cain, D.J., Campbell, K.M., 2025, Dietary bioavailability of uranium to a model freshwater invertebrate: Environmental Science and Technology, v. 59, no. 31, p. 16641-16651, https://doi.org/10.1021/acs.est.5c05140.

Publication type Article
Publication Subtype Journal Article
Title Dietary bioavailability of uranium to a model freshwater invertebrate
Series title Environmental Science and Technology
DOI 10.1021/acs.est.5c05140
Volume 59
Issue 31
Publication Date July 28, 2025
Year Published 2025
Language English
Publisher ACS Publications
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center, National Research Program - Central Branch
Description 11 p.
First page 16641
Last page 16651
Additional publication details